Safety Of Low Molecular Weight Heparin Research Articles

Comparative Efficacy of Oral Apixaban and Subcutaneous Low Molecular Weight Heparins in the Treatment of Cancer-Associated Thromboembolism: A Meta-Analysis.

Cancer patients' risk of developing venous thromboembolism (VTE) is four to seven times higher than the general population. Cancer-associated VTE (CA-VTE), is a leading cause of morbidity and mortality in cancer patients. Low Molecular Weight Heparin (LMWH) has historically been the mainstay treatment ofCA-VTE; however, complications such as bleeding and recurrent VTE make it challenging to manage these patients. Recent randomized controlled trials (RCTs) have proven that direct oral anticoagulants (DOACs) are as efficacious as LMWHs in treating CA-VTE. We conducted a systematic review and meta-analysis to ascertain the efficacy and safety of LMWH and Apixaban for the treatment of CA-VTE.A systematic review was conducted using Medline, Embase, and Scopus, databases for all cohort studies, case-control studies, and RCTs in English comparing cancer patients undergoing treatment with Apixaban or LMWH to treat CA-VTE from inception-May 2023. The Review Manager program, version 5.4.1, was used for statistical analysis and the Mantel-Haenszel fixed-effects models to calculate the risk ratio (RR) and 95% confidence intervals (CIs) and the inverse variance approach to get the weighted mean difference for the continuous outcomes. Q-test for heterogeneity was used to examine statistical heterogeneity and an I2 statistics value >50%was defined as significant heterogeneity. A total of four studies were included, and the total number of patients was 1,632 across all studies. The Apixaban group was associated with a statistically significant increase in minor bleeding (RR 1.57; 95% CI (1.12, 2.21); p=0.009; I2=0%), but not for major and total bleeding. The Apixaban group showed a statistically significant lower risk of recurrent VTE when compared to the LMWH group (RR: 0.61; 95% CI (0.41, 0.92); p=0.02; I2 = 7%), and there was no statistically significant difference in terms of mortality between the two groups (RR: 0.89;95% CI (0.73, 1.09); I2=0). Our findings suggest that Apixaban may be a favorable anticoagulant option for managing cancer-associated thromboembolism, as it demonstrated a lower risk of recurrent VTE. The risk of bleeding with DOAC in gastrointestinal cancers warrants further investigation.

Safety and efficacy of direct oral anticoagulants (DOACs) vs low molecular weight heparin (LMWH) in malignancy induced venous thromboembolism-a systematic review and meta analysis

Abstract Funding Acknowledgements Type of funding sources: None. Background- Low molecular weight heparin (LMWH) and direct oral anticoagulants (DOACs) have been proven to be more effective in the management of venous thromboembolism (MVTE). The efficacy and safety of LMWH or DOACs in treatment of recurrent or malignancy induced VTE is not studied in literature. Objective To compare the efficacy and safety of LMWH and DOACs in the management of malignancy induced VTE Methods- Electronic databases ( PubMed, Embase, Scopus, Cochrane) were searched from inception to November 28th, 2020. Dichotomous data was extracted for prevention of VTE and risk of major bleeding in patients taking either LMWH or DOACs. Unadjusted odds ratios (OR) were calculated from dichotomous data using Mantel Haenszel (M-H) random-effects with statistical significance to be considered if the confidence interval excludes 1 and p < 0.05. Results- Three studies with 2607 patients (DOACs n = 1301 ; LMWH n = 1306) were included in analysis. All the study population had active cancer of any kind diagnosed within the past 6 months. Average follow-up period for each trial was 6 months. Patients receiving DOACs have a lower odds of recurrence of MVTE as compared to LMWH( OR 1.56; 95% CI 1.17-2.09; P = 0.003, I2 = 0). There was no significant difference in major bleeding among patients receiving LMWH or DOACs (OR-0.71, 95%CI 0.46-1.10, P = 0.13, I2 = 22%) (Figure 1). We had no publication bias in our results (Egger’s regression p > 0.05). Conclusion- DOACs are superior to LMWH in prevention of MVTE and have similar major bleeding risk as that of LMWH. Abstract Figure. A)VTE Recurrence B)Major Bleeding events

Therapeutic effect of low-molecular-weight heparin on adult sepsis: a meta-analysis

Low-molecular-weight heparin (LMWH) is a part of standard supportive therapy for sepsis, but clinical research on anticoagulant therapy is still controversial. The aim of the present study was to explore the efficacy and safety of LMWH in adult septic patients by meta-analysis. Information on randomized controlled trials was retrieved from PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and China Wanfang Database from the establishment of each database to February 20, 2020. The therapeutic efficacy indexes of LMWH for adult septic patients were analyzed by Stata15.0 software. A total of 684 septic patients were included in 10 trials. The results showed that, compared with conventional treatment, LMWH significantly reduced prothrombin time [mean difference (MD) =-0.48, 95% confidence interval (CI): -0.83 to -0.13], Acute Physiology And Chronic Health Evaluation II score (MD=-4.42, 95% CI: -5.50 to -3.33), and 28-day mortality [relative risk (RR) =0.52, 95% CI: 0.38-0.70], and increased platelet count (MD =34.99, 95% CI: 23.37-46.60). LMWH significantly reduced levels of tumor necrosis factor-α, interleukin-6, and D-dimer, and the incidence of multiple organ dysfunction syndrome (MODS), with statistically significant differences. In addition, LMWH did not increase bleeding events (RR =1.29, 95% CI: 0.76-2.17). On the basis of routine treatment, LMWH can improve coagulation function, reduce inflammatory reaction and the risk of bleeding, reduce the incidence of MODS and 28-day mortality rate, and improve the prognosis of adult patients with sepsis.

Efficacy and tolerance of selective and non-selective factor Xa inhibitors in the prevention of thrombosis in kidney disease in patients with systemic lupus erythematosus and antiphospholipid syndrome

The use of factor Xa inhibitors is justified in the therapy of thrombosis in antiphospholipid syndrome (APS) and active lupus nephritis (LN). To monitor the efficacy and safety of these drugs, plasma anti-Xa (aXa) activity is determined. Objective : to assess the aXa activity of selective and non-selective factor Xa inhibitors in patients with systemic lupus erythematosus (SLE) and APS depending on how they affect the kidneys. Patients and methods. Clinical and laboratory findings were prospectively analyzed in SLE and APS patients who long received low molecular weight heparins (LMWHs) and selective Xa inhibitors, such as fondaparinux and rivaroxaban. The investigation enrolled 70 patients (54 females and 16 males) aged 39 years (range, 31 to 43 years) with SLE (n=15 (21%)), primary APS (PAPS) (n=10 (14%)), and SLE + APS (n=45 (65%)). Results . Kidney disease was diagnosed in 33 (47%) of the 70 patients. LN was detected in 15 (25%) of the 60 patients: 10 and 5 patients with SLE and SLE + APS, respectively. APS nephropathy (APSN) was manifested by elevated creatinine and urea levels with normal urine sediment and no history of glomerulonephritis and was observed in 18 (33%) of the 55 patients: in 16 with SLE + APS and 2 with PAPS. The therapeutic aXa range of 0.1—1.5 IU/ml was found in 43 (61%) of the 70 patients, low and high aXa activities were seen in 14 (20%) and 13 (19%) patients, respectively. In patients with APSN, the creatinine clearance (CC) depended on aXa levels: the highest CC was noted in patients with aXa >1.5 IU/mL, the lowest CC was in those with aXa <0.9 IU/ mL (p=0.046). The levels of aXa above the therapeutic range were more common in patients taking fondaparinux (9 (31%) out of the 29 patients) than in those using nadroparin (2 (7%) out of the 29 patients) (odds ratio (OR) 1.92; 95% confidence interval (CI), 1.25—2.97; p=0.04). In the fondaparinux group, high aXa was more frequently observed in patients with high SLE activity (7 (47%) out of the 15 patients) than in those with moderate or mild SLE activity (none out of the 7 patients) (OR 1.88; 95% CI, 1.17—3.01; p=0.037) and was unassociated with LN. The highest aXa level with no signs of hemorrhage was 2.08 IU/mL. Conclusion. The level of aXa is a qualitative laboratory marker for the efficacy and safety of LMWHs and fondaparinux. In patients with APS, the enhanced aXa activity of LMWHs and fondaparinux was associated with elevated CC and was not accompanied by hemorrhage. Fondaparinux is an effective and safe anticoagulant for the treatment and prevention of thrombosis in SLE and APS. The therapeutic window for aXa should be extended in these patients.

Low-molecular-weight-heparin versus a coumarin for the prevention of recurrent venous thromboembolism in high- and low-risk patients with active cancer: a post hoc analysis of the CLOT Study

In patients with active cancer and acute venous thromboembolism (VTE), the low-molecular-weight-heparin (LMWH) dalteparin is more effective than vitamin K antagonist (VKA) in reducing the risk of recurrent venous thromboembolism (rVTE) without increasing the risk of bleeding. However, the relative benefit of LMWH versus VKA in patients with active cancer at high or low risk of rVTE and bleeding is unclear. This post hoc analysis used data from the CLOT study to explore the efficacy and safety of LMWH versus VKA in preventing recurrent thrombosis in high- and low-risk patients with active cancer. High-risk patients were defined by metastatic disease and/or antineoplastic treatment at baseline; low-risk patients presented with neither. Among high-risk patients, rVTE occurred in 25/318 (8%) (LMWH) versus 53/314 (17%) (VKA) (hazard ratio, 0.44; p = 0.001). No significant difference was detected in the rate of major or any bleeding. The 6-month mortality rate was 40% (LMWH) versus 41% (VKA). In low-risk patients, 2/20 (10%) (LMWH) had rVTE versus 0/24 (0%) (VKA) (hazard ratio, not estimable; p = 0.998). No significant difference was detected in the rate of major or any bleeding. The 6-month mortality rate was 20% (LMWH) versus 29% (VKA). In patients with cancer-associated thrombosis at high risk of rVTE and bleeding, the LMWH dalteparin was more effective than VKA in reducing the risk of rVTE without increasing the risk of bleeding. No difference in rate of rVTE or bleeding was observed between LMWH and VKA among low-risk patients.

Efficacy and safety of low-molecular-weight heparin after knee arthroscopy: A meta-analysis.

BackgroundVenous thromboembolism (VTE) is considered a potentially serious complication of knee arthroscopy and leads to conditions such as deep venous thrombosis (DVT) and pulmonary embolism (PE). Low-molecular-weight heparin (LMWH) is widely employed in knee arthroscopy to reduce perioperative thromboembolic complications. However, the efficacy and safety of LMWH in knee arthroscopy remains unclear.MethodsSeven randomized controlled clinical trials on LMWH in knee arthroscopy were identified and included in this meta-analysis. The main outcomes of the effectiveness (prevention of DVT and PE) and complications (death, major bleeding, and minor bleeding) of LMWH in knee arthroscopic surgery were assessed using Review Manager 5.3 software.ResultsThe meta-analysis indicated that LMWH prophylaxis comprised 79% of asymptomatic DVT. No association was found in symptomatic VTE (RR: 0.90; 95% confidence interval [CI]: 0.39–2.08; P = 0.80), symptomatic DVT (RR: 0.79; 95% CI: 0.28–2.23; P = 0.66), symptomatic PE (RR: 1.36; 95% CI: 0.37–4.97; P = 0.64) and major bleeding (RR: 0.70; 95% CI: 0.12–3.95; P = 0.68) risk during LMWH prophylaxis were identified. Death was not reported in these studies. Moreover, there was a lower incidence of minor bleeding (RR: 0.64; 95% CI: 0.49 to 0.83; P = 0.001) in the control group than in the LMWH group.ConclusionCompared with the control group, the group treated with LMWH after knee arthroscopy was no association in reducing the symptomatic VTE rate, symptomatic DVT rate or symptomatic PE rate. The symptomatic VTE rate was 0.5% (11/2,166) in the LMWH group versus 0.6% (10/1,713) in the control group. Although the limitations of this meta-analysis cannot be ignored, the results of our study show that LMWH after knee arthroscopy is ineffective. We recommend that LMWH should not be routinely provided for knee arthroscopy.Trial registrationClinicalTrials.gov NCT03164746

Low molecular weight heparin does not increase bleeding and mortality post-endoscopic variceal band ligation in cirrhotic patients.

Anticoagulants are commonly indicated in cirrhotic patients due to high rate of (pro)thrombotic conditions. Low molecular weight heparin (LMWH) is safe in patients with esophageal varices. However, the safety of LMWH is unknown in patients undergoing prophylactic endoscopic variceal ligation (EVL). To define the 4-week risk of bleeding and death after prophylactic EVL in cirrhotic patients continuously treated with LMWH. All EVLs performed at a tertiary Italian Center from 2009 to 2016 were retrospectively reviewed. Patients treated with LMWH were classified as on-LMWH; the remaining as no-LMWH. Endoscopic characteristics at first and index EVL (that preceding an endoscopy either showing a bleeding episode or the absence of further treatable varices) and clinical events within 4weeks from the procedures were recorded. Five hundred fifty-three EVLs were performed in 265 patients (in 215 as a primary prophylaxis): 169 EVLs in 80 on-LMWH and 384 in 185 no-LMWH (4.9±1.1 vs 4.8±1.0 bands/session, respectively; P=.796). Six patients bled (2.2%) without between-groups difference (3.8% on-LMWH vs 1.6% no-LMWH, Log-rank P=.291). Large varices with red marks (100% vs 51.4%, P=.032), number of bands (5.6±0.5 vs 4.6±1.2, P=.004), underlying portal vein thrombosis (66.7% vs 23.6%, P=.033), and creatinine (2.2±2.7 vs 1.0±0.8mg/dL, P=.001) at index EVL were significantly different between bleeders and non-bleeders. Six patients died within 4-week from index EVL, without between-groups difference (2.5% on-LMWH vs 2.2% no-LMWH, Log-rank P=.863). LMWH does not increase the risk of post-procedural bleeding and does not affect survival of cirrhotic patients undergoing prophylactic EVL.

The Khorana Score for the Prediction of Venous Thromboembolism in Patients with Solid Cancer: An Individual Patient Data Meta-Analysis

Background: Guidelines suggest the use of the Khorana score to select patients with solid cancer receiving chemotherapy for thromboprophylaxis to prevent venous thromboembolism (VTE), but its performance in different types of cancers remains uncertain.Methods: The present analysis includes individual patient data from seven randomized controlled trials that had compared prophylactic (ultra)-low-molecular-weight heparin (LMWH) with placebo or observation in patients with solid cancer. The analysis addresses the performance of the continuous and dichotomized Khorana score in predicting the 6-month risk of VTE in the trial control groups, overall and in types of cancer studies, as well as the efficacy and safety of LMWH among patients with a high-risk Khorana score. Random effects meta-analysis provided the basis for summary estimates.Findings: In the 3,403 patients from the control groups included in the analyses, the mean age was 61 years, 59% were male, and 58% had lung cancer. During 6-months of follow-up, 188 patients (5.5%) developed VTE. Overall, the 6-month VTE incidence was 9.8% among high-risk Khorana score patients and 6.4% among low-to-intermediate risk patients (OR 1.6; 95%-CI 1.1-2.2). The dichotomous Khorana score performed differently in lung cancer patients (OR 1.1; 95%-CI, 0.72-1.7) than in those with other types of cancer (OR 4.4; 95%-CI, 2.7-7.3; P interaction=0.002). Among high-risk patients, LMWH decreased the risk of VTE by 64% compared to placebo or observation (OR 0.36; 95%-CI, 0.22-0.58). In the group of patients with types of cancer other than lung cancer and a high-risk Khorana score (N=619), the 6-month VTE incidence was 3.3% (95% CI, 1.4 to 7.7) among LMWH recipients and 13% (95% CI, 6.8 to 24) among those not receiving LMWH (OR 0.23, 95% CI, 0.11 to 0.46; P <0.001). There was no difference in major bleeding (OR 1.2, 95% CI, 0.56 to 2.5).Interpretation: The Khorana score performs poorly in differentiating between those at high and low risk of VTE in patients with lung cancer, but is associated with a 4-fold increased risk of VTE in those with other types of cancer. Thromboprophylaxis is effective and safe in patients with a high-risk Khorana score.Funding: Canadian Institutes of Health Research knowledge synthesis grant, KRS 126594Registration: International Prospective Register for Systematic Reviews (PROSPERO), CRD42013003526. DisclosuresVan Es:Pfizer: Employment, Other: Comment: Dr. van Es reports personal fees from Pfizer as a member of their advisory board. These fees are unrelated to this project.. Crowther:Alexion: Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Boehringer Ingelheim: Speakers Bureau; Leo Pharma: Research Funding; Pfizer: Honoraria; Portola: Consultancy; Shinogi: Consultancy. Macbeth:Cancer Research UK: Research Funding; Pfizer: Other: Provision of Dalteparin for FRAGMATIC trial. Griffiths:Pfizer: Consultancy, Other: Comment: I run an academic clinical trials unit, have received educational/investigator intiated research grants from companies that make these heparin agents. As consultant > 3 years ago, advised Pfizer on clinical trial designs unrelated to this study., Research Funding. Streiff:Roche: Research Funding; Portola: Research Funding; Janssen Scientific Affairs, LLC: Consultancy, Research Funding; CSL Behring: Consultancy, Research Funding. Ageno:Daiichi Sankyo: Consultancy, Honoraria; Bayer AG: Consultancy, Honoraria, Research Funding; BMS-Pfizer: Consultancy, Honoraria; Boehringer Ingelheim: Consultancy, Honoraria. Bozas:PharmaMar: Honoraria. Maraveyas:Bayer: Other: Personal fees and conference attendance; Bristol-Myers Squibb: Other: Grants and personal fees; Leo Pharma: Other: Grants, personal fees and conference attendance; Pfizer: Other: Personal fees. Loprinzi:Bristol Myers: Other: Grant - unrelated to this project; Janssen: Other: Grant - unrelated to this project. McBane:Bristol Myers Squibb: Other: Research grant for cancer associated VTE. Schünemann:Canadian Institutes of Health Research: Research Funding.

VTE risk assessment in cancer. Who needs prophylaxis and who does not?

Venous thromboembolism (VTE) in patients with cancer is associated with an increased morbidity and mortality, and its prevention is of major clinical importance. However, the VTE rates in the cancer population vary between 0.5% - 20%, depending on cancer-, treatment- and patient-related factors. The most important contributors to VTE risk are the tumor entity, stage and certain anti-cancer treatments. Cancer surgery represents a strong risk factor for VTE, and medical oncology patients are at increased risk of developing VTE, especially when receiving chemotherapy or immunomodulatory drugs. Also biomarkers have been investigated for their usefulness to predict risk of VTE (e.g. elevated leukocyte and platelet counts, soluble P-selectin, D-dimer, etc.). In order to identify cancer patients at high risk of VTE and to improve risk stratification, risk assessment models have been developed, which contain both clinical parameters and biomarkers. While primary thromboprophylaxis with low-molecular-weight-heparin (LMWH) is recommended postoperatively for a period of up to 4 weeks after major cancer surgery, the evidence is less clear for medical oncology patients. Thromboprophylaxis in hospitalized medical oncology patients is advocated, and is based on results of randomized controlled trials which evaluated the efficacy and safety of LMWH for prevention of VTE in hospitalized medically ill patients. In recent trials the benefit of primary thromboprophylaxis in cancer patients receiving chemotherapy in the ambulatory setting has been investigated. However, at the present stage primary thromboprophylaxis for prevention of VTE in these patients is still a matter of debate and cannot be recommended for all cancer outpatients.

VTE risk assessment in cancer

SummaryVenous thromboembolism (VTE) in patients with cancer is associated with an increased morbidity and mortality, and its prevention is of major clinical importance. However, the VTE rates in the cancer population vary between 0.5% - 20%, depending on cancer-, treatment- and patient-related factors. The most important contributors to VTE risk are the tumor entity, stage and certain anticancer treatments. Cancer surgery represents a strong risk factor for VTE, and medical oncology patients are at increased risk of developing VTE, especially when receiving chemotherapy or immunomodulatory drugs. Also biomarkers have been investigated for their usefulness to predict risk of VTE (e.g. elevated leukocyte and platelet counts, soluble P-selectin, D-dimer, etc.). In order to identify cancer patients at high risk of VTE and to improve risk stratification, risk assessment models have been developed, which contain both clinical parameters and biomarkers. While primary thromboprophylaxis with lowmolecular- weight-heparin (LMWH) is recommended postoperatively for a period of up to 4 weeks after major cancer surgery, the evidence is less clear for medical oncology patients. Thromboprophylaxis in hospitalized medical oncology patients is advocated, and is based on results of randomized controlled trials which evaluated the efficacy and safety of LMWH for prevention of VTE in hospitalized medically ill patients. In recent trials the benefit of primary thromboprophylaxis in cancer patients receiving chemotherapy in the ambulatory setting has been investigated. However, at the present stage primary thromboprophylaxis for prevention of VTE in these patients is still a matter of debate and cannot be recommended for all cancer outpatients.

Early postoperative bridging anticoagulation after mechanical heart valve replacement: a systematic review and meta‐analysis

To perform a systematic review and meta-analysis of studies evaluating anticoagulation during the early postoperative period following mechanical heart valve implantation. Five literature databases were searched to assess the rates of bleeding and thromboembolic events among patients receiving oral anticoagulation (OAC), both with and without bridging anticoagulation therapy with unfractionated heparin (UFH) or subcutaneous low molecular weight heparin (LMWH). The studies' results were pooled via a mixed effects meta-analysis. Heterogeneity (I(2) ) and publication bias were both evaluated. Twenty-three studies including 9534 patients were included. The bleeding rates were 1.8% (95% confidence interval CI1.0-3.3) in thegroup receiving OAC, 2.2% (95%CI0.9-5.3) in the OAC+UFH group, and 5.5% (95%CI2.9-10.4) in the OAC+LMWH group (P=0.042). The thromboembolic event rate was 2.1% (95%CI1.5-2.9) in the group receiving OAC, as compared with 1.1% (95%CI0.7-1.8) when the bridging therapy groups were combined as follows: OAC+UFH and OAC+LMWH (P=0.035). Most of the analyses showed moderate heterogeneity and negative test results for publication bias. Bridging therapy following cardiac valve surgery was associated with a lower thromboembolic event rate, although the difference was small, with considerable overlap of the CIs. Direct comparisons are missing. Bridging therapy with UFH appears to be safe; however, this observation has a risk of bias. Early bridging therapy with LMWH appears to be associated with consistently high bleeding rates across multiple analyses. On the basis of the quality of the included studies, more trials are necessary to establish the clinical relevance of bridging therapy and the safety of LMWH.

The safety of low molecular-weight heparin after blunt liver and spleen injuries

BackgroundAnticoagulation is routinely administered to all trauma patients owing to the high incidence of venous thromboembolism (VTE). However, the timing of administration of anticoagulation is not clearly defined when patients have blunt spleen or liver injuries because of the perceived risk of hemorrhage with early administration. MethodsA retrospective chart review was performed of all blunt trauma patients who sustained blunt liver and/or spleen injuries during the 5-year period from 2007 to 2011. Data were collected for all patients managed with nonoperative therapy for these injuries while also receiving routine prophylactic anticoagulation with low molecular-weight heparin. Patients were categorized based on the initiation of enoxaparin therapy after injury: early (<48 hours), intermediate (48 to 72 hours), and late (>72 hours). Primary and secondary outcomes were designated as need for operative or radiologic intervention secondary to spleen or liver hemorrhage, number of transfusions, and incidence of VTE. ResultsThree hundred and twenty-eight patients were included. There were no enoxaparin-related hemorrhagic complications or hemorrhage necessitating operative intervention. Patients in the early, intermediate, and late groups received an average of .9, .93, and 1.55 units of blood, respectively. There was 1 pulmonary embolism in the early group, and there were 6 VTE complications in the late group (3 deep venous thromboses and 3 pulmonary embolisms). ConclusionsThere are currently no standards for the initiation of prophylactic anticoagulation in trauma patients with blunt liver and spleen injuries. Early administration may be safe and reduce the incidence of thrombotic complications in patients with blunt spleen and liver injuries. Prospective studies in this area are warranted.

Low molecular weight heparin versus unfractionated heparin for perioperative thromboprophylaxis in patients with cancer.

The choice of the appropriate perioperative thromboprophylaxis in patients with cancer depends on the relative benefits and harms of low molecular weight heparin (LMWH) and unfractionated heparin (UFH). To update a systematic review of the evidence for the relative efficacy and safety of LMWH and UFH for perioperative thromboprophylaxis in patients with cancer. We performed a comprehensive search for trials of anticoagulation in patients with cancer including a February 2013 electronic search of: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE. We also handsearched conference proceedings, reviewed reference list of included studies, used the 'related citations' feature in PubMed, and searched clinicaltrials.gov for ongoing studies. Randomized controlled trials (RCTs) that enrolled patients with cancer undergoing a surgical intervention and compared the effects of LMWH to UFH on mortality, deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding outcomes, or thrombocytopenia. Two review authors independently used a standardized form to extract in duplicate data on participants, interventions, outcomes of interest, and risk of bias. Where possible, we conducted meta-analyses using the random-effects model. Of 9559 identified unique citations, we included 16 RCTs with 12,890 patients with cancer, all using preoperative prophylactic anticoagulation. We identified no new study with this update. The overall quality of evidence was moderate. The meta-analyses did not conclusively rule out either a beneficial or harmful effect of LMWH compared with UFH for the following outcomes: mortality (risk ratio (RR) 0.89; 95% confidence interval (CI) 0.74 to 1.08), PE (RR 0.73; 95% CI 0.34 to 1.54), symptomatic DVT (RR 0.50; 95% CI 0.20 to 1.28), asymptomatic DVT (RR 0.81; 95% CI 0.66 to 1.01),major bleeding (RR 0.85; 95% CI 0.52 to 1.37), and minor bleeding (RR 0.92; 95% CI 0.47 to 1.79). LMWH was associated with lower incidence of wound hematoma (RR 0.68; 95% CI 0.52 to 0.88) but higher volume of intraoperative transfusion (mean difference (MD) 74 mL; 95% CI 47 to 102). The meta-analyses found no statistically significant differences for any of the following outcomes: reoperation for bleeding (RR 0.72; 95% CI 0.06 to 8.48) , intraoperative blood loss (MD= -6mL; 95% CI -87 to 74), postoperative transfusion (MD= 79mL; 95% CI -54 to 211), postoperative drain volume (MD= 27mL; 95% CI -44 to 98), and thrombocytopenia (RR 1.33; 95% CI 0.59 to 3.00). We found no difference between perioperative thromboprophylaxis with LMWH versus UFH in their effects on mortality, thromboembolic outcomes, major bleeding, or minor bleeding in patients with cancer. Further trials are needed to evaluate the benefits and harms of different heparin thromboprophylaxis strategies in this population more thoroughly.

Efficacy and safety of low molecular weight heparin in patients with mechanical heart valves: systematic review and meta‐analysis

Low molecular weight heparins (LMWHs) are not approved for patients with mechanical heart valves (MHVs). However, in several guidelines, temporary LMWH off-label use in this clinical setting is considered to be a valid treatment option. Therefore, we reviewed the efficacy and safety of LMWHs in patients with MHVs. MEDLINE and CENTRAL databases were searched from inception to June 2013. Review articles and references were also searched. We included experimental and observational studies that compared LMWHs with unfractionated heparin (UFH) or vitamin K antagonists (VKAs). Data were analyzed and pooled to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for thromboembolic and major bleeding events. Statistical heterogeneity was evaluated with the I(2) -test. Nine studies were included: one randomized controlled trial (RCT) and eight observational studies, with a total of 1042 patients. No differences were found between LMWHs and UFH/VKAs in the risk of thromboembolic events (OR 0.67; 95% CI 0.27-1.68; I(2) = 9%) or major bleeding events (OR 0.66; 95% CI 0.36-1.19; I(2) = 0%). The best evidence available might support the temporary use of LMWHs as a prophylactic treatment option in patients with MHVs. However, conclusions are mostly based on observational data (with large CIs), and an adequately powered RCT is urgently needed in this clinical setting.

CP-012 Incidence and prevention of venous thromboembolism in surgical breast cancer patients

BackgroundVenous thromboembolism (VTE) is a serious and potentially fatal consequence of certain disease states and medical interventions, including hospitalisation and surgery. Surgical interventions are classified as high, moderate and low...

Low molecular weight heparin for prevention of microvascular occlusion in digital replantation

The success of digital replantation is highly dependent on the patency of the repaired vessels after microvascular anastomosis. Antithrombotic agents are frequently used for preventing vascular occlusion. Low molecular weight heparin (LMWH) has been reported to be as effective as unfractionated heparin (UFH) in peripheral vascular surgery, but with fewer adverse effects. Its benefit in microvascular surgery such as digital replantation is unclear. To assess whether subcutaneous LMWH treatment improves the salvage rate of the digits in patients with digital replantation after traumatic amputation. The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (October 2012), CENTRAL (2012, Issue 10) and trials databases. In addition, the authors searched PubMed, CNKI (China National Knowledge Infrastructure) and CEPS (Chinese Electronic Periodical Services), and sought additional trials from reference lists of relevant publications. We selected randomised or quasi-randomised controlled trials of LMWH in patients who received digital replantation. Two review authors independently extracted data and assessed the risk of bias of the included trials. Disagreements were resolved by discussion. Two randomised trials involving 114 patients with at least 122 replanted digits met the inclusion criteria and were included. Both trials compared the efficacy and safety of LMWH with UFH. We found no trials comparing LMWH with placebo or other anticoagulants. The data from the two included studies were insufficient for meta-analysis. The overall success rate of replantation did not differ between the LMWH and UFH groups, 92.3% versus 89.2% in one trial (risk ratio (RR) 1.03; 95% confidence interval (CI) 0.87 to 1.22) and 94.3% versus 94.15% in the other trial (RR 1.00; 95% CI 0.89 to 1.13). The incidence of both postoperative arterial and venous insufficiency were reported in one trial and did not significantly differ between the LMWH and UFH groups (RR 1.08; 95% CI 0.16 to 7.10 and RR 0.81; 95% CI 0.20 to 3.27, respectively). Direct and indirect causes of microvascular insufficiency were not reported in the trials. Different methods were used to monitor the adverse effects related to anticoagulation in the two trials. Bleeding tendency was monitored for the LMWH and UFH groups in one trial and was reported by the incidence of wound haemorrhage (11.5% versus 17.9%; RR 0.65; 95% CI 0.17 to 2.44), ecchymoses (3.8% versus 10.7%; RR 0.36; 95% CI 0.04 to 3.24), haematuria (3.8% versus 7.1%; RR 0.54; 95% CI 0.05 to 5.59), nasal bleeding (0% versus 7.1%; RR 0.21; 95% CI 0.01 to 4.28), gingival bleeding (0% versus 10.7%; RR 0.15, 95% CI 0.01 to 2.83) and faecal occult blood (0% versus 3.6%; RR 0.36; 95% CI 0.02 to 8.42). The bleeding tendency was increased in the UFH group but this was not statistically significant. This trial also monitored coagulability changes using parameters such as antithrombin activity, factor Xa activity, bleeding time, clotting time and activated partial thromboplastin time (aPTT). No comparison was made between the LMWH and UFH groups but all data consistently showed that coagulability was reduced more in the UFH group than in the LMWH group. The other trial reported a postoperative decrease in platelet count in the UFH group (preoperative 278.4 ± 18.7 x 10(9)/L, postoperative 194.3 ± 26.5 x 10(9)/L; P < 0.05) but not in the LMWH group (preoperative 260.8 ± 32.5 x 10(9)/L, postoperative 252.4 ± 29.1 x 10(9)/L; P > 0.05). Current limited evidence based on two small-scaled low-to-medium quality randomised trials found no differences in the success rate of replantation between LMWH and UFH, but a lower risk of postoperative bleeding and hypocoagulability after the use of LMWH. Further well-designed and adequately powered clinical trials are warranted.

Prevention of venous thromboembolism in hospitalized patients with chronic kidney disease

Despite the high morbidity and mortality associated with venous thromboembolism in hospitalized medical patients with a number of risk factors, and large evidence that prophylaxis is effective, prophylaxis rates remain elusive in medically ill patients. Furthermore, in patients with renal failure, prophylaxis often is omitted or sub-optimal, due to fear of provoking hemorrhage. Patients with end-stage renal disease often have platelet deficits. Low molecular weight heparin (LMWH) therapy may also be difficult to manage in these cases because LMWH clearance is largely dependent on the kidneys. Administration of LMWH to patients with some degree of renal failure may lead to bioaccumulation of anti-Xa activity with an increased risk of bleeding. In recent years, LMWH has largely replaced unfractionated heparin (UFH) for the treatment and prophylaxis of thromboembolic disease. LMWHs have been shown to be superior to UFH in the prevention of venous thromboembolism. They are also easier to administer and do not require laboratory monitoring. However, several case reports and a metaanalysis indicate that the use of LMWHs at therapeutic doses in patients with advanced renal failure can be associated with major bleeding with serious adverse effects. In this paper, we review recent evidence supporting the safety of LMWHs at prophylactic doses in patients with mild or moderate renal disease. Current evidence suggests that bioaccumulation of enoxaparin (the most widely used LMWH) can occur when the drug is used at standard therapeutic doses in patients with severely impaired renal function. This risk can be reduced by empiric dose reduction or monitoring of anti-Xa heparin levels.

Low-Molecular-Weight Heparin and Early Neurologic Deterioration in Acute Stroke Caused by Large Artery Occlusive Disease

Patients with acute ischemic stroke and large artery occlusive disease (LAOD) have an increased risk for early neurologic deterioration (END) due to progressive stroke, early recurrent ischemic stroke(ERIS), or symptomatic intracranial cerebral hemorrhage(SICH). Low-molecular-weight heparin (LMWH)has been widely advocated to prevent venous thromboembolism,but its risks and benefits in early ischemic stroke are inadequately defined. To determine the efficacy and safety of LMWH in treating END in patients with acute ischemic stroke and LAOD. Post hoc analysis of randomized, controlled trial. Academic research. Among 603 patients recruited, 353 patients(180 treated with LMWH, 173 with aspirin) had acute ischemic stroke and LAOD. Patients were randomly assigned to receive either subcutaneous LMWH or oral aspirin within 48 hours after stroke onset for 10 days, then all received aspirin once daily for 6 months. We assessed whether LMWH was superior to aspirin for the prevention of END within the first 10 days after index stroke. Early neurologic deterioration was defined as a composite end point of progressive stroke, ERIS, and SICH. Among 353 patients included in the study, END within the first 10 days occurred in 6.7% of LMWH allocated patients (12 of 180 patients) compared with 13.9% of aspirin-allocated patients (24 of 173). Low molecular-weight heparin was significantly associated with the reduction of END(absolute risk reduction, 7.2%; odds ratio [OR], 0.44; 95% CI, 0.21-0.92). When individual components of END were examined, LMWH was significantly associated with a lower frequency of stroke progression within the first 10 days compared with aspirin(5.0% [9 of 180] vs 12.7% [22 of 173]; OR, 0.36; 95%CI, 0.16-0.81). Meanwhile, among those taking LMWH vs aspirin, the frequency rates of ERIS were 1.1% (2 of 180) vs 0 (0); 0.6% (1 of 180) vs 1.2% (2 of 173) for SICH;and 2.2% (4 of 180) vs 2.9% (5 of 173) for symptomatic and asymptomatic cerebral hemorrhage, respectively; they showed nonsignificant trends. Early neurologic deterioration was significantly associated with 6-month disability with both LMWH(OR, 12.75; 95% CI, 3.27-49.79 on Barthel Index and OR, 18.15; 95% CI, 2.09-157.93 on modified Rankin Scale) and aspirin (OR, 6.09; 95% CI,2.44-15.20 on Barthel Index and OR, 7.50; 95% CI, 2.08-27.04 on modified Rankin Scale) groups. For patients with acute ischemic stroke and LAOD, treatment with LMWH within 48 hours of stroke may reduce END during the first 10 days, mainly by preventing stroke progression. The similar rate of cerebral hemorrhage between LMWH and aspirin demonstrated that LMWH may be safely used in acute ischemic stroke. stroke center.org/trials Identifier: FISS -tris

Tu1229 Efficacy and Safety of Low-Molecular Weight Heparin for the Prevention of Venous Thromboembolism in Patients With Severe Ulcerative Colitis

Tu1229 Efficacy and Safety of Low-Molecular Weight Heparin for the Prevention of Venous Thromboembolism in Patients With Severe Ulcerative Colitis

P306 Efficacy and safety of low-molecular weight heparin for the prevention of venous thromboembolism in patients with severe ulcerative colitis

P306 Efficacy and safety of low-molecular weight heparin for the prevention of venous thromboembolism in patients with severe ulcerative colitis A. Papa1 *, A. Armuzzi2, L. Guidi3, I. De Vitis4, G. Mocci5, C. Felice4, M. Marzo6, D. Pugliese1, G.L. Rapaccini7. 1Catholic University of Rome, Internal Medicine and Gastroenterology Complesso Integrato Columbus, Rome, Italy, 2Complesso Integrato Columbus, Gastroenterology Unit, Rome, Italy, 3Universita Cattolica Del Sacro Cuore, O.U. Gastroenterology Columbus, Rome, Italy, 4Universita Cattolica Del Sacro Cuore, Complesso integrato Columbus/OU of Internal Medicine and Gastroenterology, Rome, Italy, 5Catholic University of Rome, Internal Medicine Gastroenterology, Rome, Italy, 6Complesso Integrato Columbus, Medicina Interna e Gastroenterologia, Rome, Italy, 7Catholic University of Rome, Complesso Integrato Columbus/OU of Internal Medicine and Gastroenterology, Rome, Italy